A hearing impaired person typically suffers from a loss of hearing sensitivity which loss is dependent upon both frequency and the level of the sound in question. Thus a hearing impaired person may be able to hear certain frequencies (e.g., low frequencies) as well as a normal hearing person, but unable to hear sounds with the same sensitivity as a normal hearing individual at other frequencies (e.g., high frequencies). Similarly, the hearing impaired person may perceive loud sounds, e.g. above 90 dB SPL, with the same intensity as the normal hearing person, but still unable to hear soft sounds with the same sensitivity as the normal hearing person. Thus, in the latter situation the hearing impaired person suffers from a loss of dynamic range at certain frequencies or frequency bands. In addition to the above-mentioned frequency and level dependent hearing loss of the hearing impaired person loss often leads to a reduced ability to discriminate between competing or interfering sound sources for example in a noisy sound environment with multiple active speakers and/or noise sound sources. The healthy hearing system relies on the well-known cocktail party effect to discriminate between the competing or interfering sound sources under such adverse listening conditions. The cocktail party effect relies inter alia on spatial auditory cues from the competing or interfering sound sources to perform the discrimination based on spatial localization of the competing sound sources. Under such adverse listening conditions, the SNR of sound received at the hearing impaired individual's ears may be so low that the hearing impaired individual is unable to detect and use the spatial auditory cues to discriminate between different sound streams from the competing sound sources. This leads to a severe worsened ability to hearing and understanding speech in noisy sound environments for many hearing impaired persons compared to normal hearing subjects. There exist several common ways of addressing the problem by exploiting SNR enhancing techniques to the hearing aid microphone signal(s) such as single-channel noise reduction algorithms or fixed or adaptive beamforming algorithms to provide enhanced speech intelligibility or quality to hearing aid user. On the other hand there are many situations where the hearing aid user is able to do well without applying any advanced speech processing algorithms in the hearing aid. In these situations, it may be beneficial to avoid introducing more than a required amount of processing because the hearing aid user might not benefit from these and the advanced algorithms may introduce annoying sound artifacts.